BACKGROUNDTo investigate the relations between metabolizing enzymes' genetic polymorphism and lung cancer risk in Chinese, especially in heavy smokers.

METHODSCYP1A1, 2D6, 2E1 and GSTM1 genotypes were detected in 180 patients with lung cancer and 224 controls by PCR-based genotype assays.

RESULTSCYP1A1 variant allele, CYP2D6 wild allele, CYP2E1 A genotype, GSTM1-null genotype were found to be associated with lung cancer. The individuals who carried GSTM1-null genotype and one of the CYP1A1, CYP2D6, CYP2E1 'in risk' genotypes had a 2.24-2.69 fold increased risk of lung cancer. The heavy smokers had a significantly increased risk of lung cancer than the non-smokers who carried the same genotype of metabolizing enzymes. The heavy smoker who carried all the four 'in risk' genotypes of metabolizing enzymes had an obviously increased risk of lung cancer (OR=9.85, 95%CI=2.30-45.71).

CONCLUSIONSThe individuals who carry the 'in risk' genotype of metabolizing enzymes have an increased risk of lung cancer. It is positively associated with tobacco carcinogen dose.